Non-structural partition tabbing question

Discussion in 'Fiberglass and Composite Boat Building' started by Tkarrde, Feb 2, 2021.

  1. Tkarrde
    Joined: Feb 2021
    Posts: 2
    Likes: 0, Points: 1
    Location: ME

    Tkarrde New Member

    So I hate to ask questions after the work is done but that's where I find myself.

    Quick summary:

    36' Downeast work boat, built in the 70s, solid glass, very thick laminate: 1.5-1.75" at keel, 3/4-7/8" at hull bottom, about 1/2" hull sides.

    I have read many threads on here and my understanding is that commercial boatbuilders in Maine rarely left (and still rarely leave) gaps in their bulkhead framing, and I'm guessing that the thickness of these hulls is more forgiving than a production boat. Indeed my 1 true structural bulkhead appears to be "tight" to the hull side, maybe 1/16" gap, no fillet.

    Had 4 non-structural (boats were built and put to work without them) trunk cabin walls that were 3/4" ply, tabbed to the hull sides only by a layer of CSM. No fillets.

    I removed those walls, templated off them, and installed new ply. I ran a layer of 1708 tape, fillet of hull and deck, then another layer of 1708. The walls are also attached to the interior trunk cabin sides and roof by screws, and tied into longitudinal bunks/storage.

    In 3 of the 4 walls, as luck would have it I have a gap varying 1/8" - 1/2" off the hull. I was not thoughtful about a gap or not because I wasn't aware of the practice of leaving one.

    On 1 of the 4 walls, I cant tell how much of a gap there is because of my fillet but it looks like the wall may be just off the hull side on 1 of the sides and/or touching the hull side thanks to the hull curvature in toward the bow (certainly not force fit, but I cant tell if its touching).

    I have read all the debates on foam beds, gap or no gap, etc.

    Should I cut that wall's glass/fillet off, cut back the plywood 1/4" off the hull just to be 100% sure, then redo the glass? Or am I overthinking it?

    Thank you
     
  2. Blueknarr
    Joined: Aug 2017
    Posts: 1,232
    Likes: 290, Points: 83
    Location: Colorado

    Blueknarr Senior Member

    I wouldn't bother.

    Thick solid hulls are far more resilient to hard spot hinging than thin or cored hulls.

    You didn't have issues before.
    You actually reduced the possibility of a hard/hinge.
     
    bajansailor likes this.
  3. fallguy
    Joined: Dec 2016
    Posts: 5,258
    Likes: 1,006, Points: 123, Legacy Rep: 10
    Location: usa

    fallguy Senior Member

    What bk said.

    The only way I'd cut and retab is if you are seeing the bh showing now.

    The workboat is probably not subject to high forces or impacts either.
     
    bajansailor likes this.

  4. Tkarrde
    Joined: Feb 2021
    Posts: 2
    Likes: 0, Points: 1
    Location: ME

    Tkarrde New Member

    Thanks guys. So trust me when I say I dont want to redo the tabbing on that 1 wall. I just want to be at peace with my decision because I dont want to run into any problems down the road.

    The hull cruises at like 14-15 knots. It's also painted, and I am aware paint is more brittle/flexes less than gelcoat. I do see some small surface cracks here and there on the hull sides, including around the location of some walls/bulkhead. The builder and surveyor's attitudes when I asked about that were : it's a 44 year old hull that's seen it all out there, some stress cracks in paint are normal. And I agree with that.

    So while there are no guarantees in life I just want to be "extra sure" that there isnt a significant issue if a 1.5-2' section of one side of the wall (because hull is angling in toward bow) is almost touching/just touching the hull side in one place.

    I do understand that even if it is, the 1708 and fillet should reduce a hard spot more than the "no fillet & CSM" that lasted 45 years...but I just want to double check given the collective wisdom here :)

    TY!!
     
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